Strange overheat issues. Melted my check valve...

Smgbad

Petty Officer 3rd Class
Joined
Jul 25, 2020
Messages
86
Evening all. Welcome to the latest edition of "Still trying to get this 86 E150 water ready".

Just went outside after work today to add rtv sealant to both hermostat housing gaskets to stop the leaks from where I installed them without it last week. When I first got the boat I had found that someone had removed the white plastic check valve on one side and the other was melted, and thermostats were also removed completely. The check valve relief holes in the housing were plugged and sealed with flex seal... I had just finished adding them back in with all brand new parts.

Well... I got them in with the rtv sealant and now after a few minutes of running, steam started coming from the water jacket gasket and then out of the check valve hole like a tea kettle that's whistling letting you know it's ready. I stopped the engine and took the housing back off. The white plastic check valve poppet is completely melted to the spring. It was brand new... Thermostat was open and it closed as it cooled off.

Tried putting it back together without the check valve and it started spewing super hot water from the check valve hole once started. What could be causing this to happen? Should I just put it back the way it was with no tstats or check valves?

Also worth noting is I just sourced a new old stock temp sensor for it as both of the ones it had when I got it were dry rotted/crumbing and nonfunctional.

Would running it without the tstats and check valves really be a horrible thing if I don't really care about gas mileage?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,108
What is the condition of parts called -------" deflector "-----In your engine.------They are installed in the block to guide cooling water through the engine.-------And are the head gaskets installed correctly ?------Any pictures of the " tabs " on the head gaskets ?----Pictures showing these tabs at the top of the block ?
 

Smgbad

Petty Officer 3rd Class
Joined
Jul 25, 2020
Messages
86
What is the condition of parts called -------" deflector "-----In your engine.------They are installed in the block to guide cooling water through the engine.-------And are the head gaskets installed correctly ?------Any pictures of the " tabs " on the head gaskets ?----Pictures showing these tabs at the top of the block ?

I'll try and get these to get you the answers you seek this evening. I see the deflector in the parts breakdown. Whats the best way to get to them for inspection? What am I looking for when I get there? Dry-rotted hoses or blockages in them?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,108
The deflectors are hoses.-----But the water does NOT GO THROUGH these hoses.------They are simply inserted into the block to guide water through the bock !!----Heads have to be removed to make sure they are there and not deformed / shifted / swollen and blocking flow of water past them.
 
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